As shown in FIGS. 1 and 2 conventional aneroid sphygmomanometers comprise a single gauge having a single needle. Therefore, when a patient must measure his own blood pressure, he must carefully watch the needle movement and memorize the systolic and diastolic pressures as the needle drops.
A patient unskilled in measuring blood pressure is apt to make mistakes in memorizing the blood pressure values. Especially in the case of an older patient, or those who cannot see well, a faulty measurement is likely to occur.